The differential interface standard (for example, LVDS (Low Voltage Differential Signaling)) is adopted to devices such as a server, a router, and a storage in which high-speed digital signals of several Gbit/s or higher are handled, and differential signals are transmitted by using a differential signal transmission cable between devices or between circuit boards in the device. The differential signals have such an advantage as high noise immunity to exogenous noises while achieving low voltage of a system power supply.
A general differential signal transmission cable is provided with: a pair of signal conductors arranged in parallel to each other; an insulator for covering these signal conductors; a shield tape wound around the insulator; and a holding tape wound around the shield tape. To the signal conductors, a plus-side (positive) signal and a minus-side (negative) signal, whose phases are reversed by 180 degrees, are transmitted, respectively. A potential difference between these two signals (the plus-side signal and the minus-side signal) becomes a signal level, and the signal level can be identified on a reception side as, for example, “High” when the potential difference is positive and “Low” when it is negative.
Here, the shield tape has a sheet-shaped base member and a metal conductor layer formed on one surface of the base member. The shield tape is wound around the insulator in longitudinal wrapping so that the metal conductor layer faces outside (see Japanese Patent Application Laid-Open Publication No. 2012-169251 (Patent Document 1)).